Proposal: Integration test checking examples on apiblueprint.org website

Builds on top of #19.

https://trello.com/c/ObThuTMy/1755-proper-testsuite-for-api-blueprint-api-app

Added integration test checking whether examples from apiblueprint.org website pass through correctly. This should prevent things like #16.
I don't like it much either, but that's the best what I could think of - getting the examples from GitHub or directly from apiblueprint.org. Running a local installation (or... just checking the file `index.html` locally would be sufficient) would mean I'd have to checkout `gh-pages` somewhere first :-/